This invention relates to mobile x-ray fluoroscopic imaging systems with miniature C-arm apparatus, and more particularly to miniature C-arm apparatus providing visual indicators to alert the physician and others to the activation of the x-ray source function of the system.
In present-day medical practice, x-ray fluoroscopic imaging systems provide images of bone and tissue that are similar to conventional film x-ray shadowgrams but are produced by conversion of an incident x-ray pattern to a "live" enhanced (intensified) optical image that can be displayed on a video monitor directly, i.e., essentially contemporaneously with the irradiation of the patient's body or body portion being imaged. The term "fluoroscopic imaging" is used herein to designate such provision of directly video-displayed x-ray images. An imaging device, including an image intensifier, suitable for use in such a system is described in U.S. Pat. No. 4,142,101, which is incorporated herein in its entirety by this reference.
In some x-ray fluoroscopic imaging systems, the entire system is carried on an easily movable cart and an x-ray source and detector are mounted on a rotatable mini C-arm dimensioned for examining smaller body parts such as the extremities (wrists, ankles, etc.) of a human patient.
One illustrative example of a commercially available mini C-arm x-ray fluoroscopic imaging system is that sold under the trade name "FluoroScan III" by FluoroScan Imaging Systems, Inc., of Northbrook, Ill. Further examples of mini C-arm x-ray fluoroscopic imaging systems are described in U.S. Pat. No. 5,627,873 and copending U.S. patent application Ser. No. 09/199,952, filed Nov. 24, 1998 (and assigned to the same assignee as the present application), both of which are incorporated herein in their entirety by this reference.
Mini C-arm x-ray fluoroscopic imaging systems are also being used to measure bone mineral density (BMD) of bones in, for example, the forearm or wrist, or in the ankle or heel (calcaneal region) of a human patient. An example of such an x-ray fluoroscopic imaging system is described in allowed copending U.S. patent application Ser. No. 08/794,615 filed on Feb. 3, 1997 which is assigned to Hologic, Inc., the parent company of the assignee of the present application, and which is incorporated herein in its entirety by this reference.
Generally, such mini C-arm x-ray fluoroscopic imaging systems and x-ray bone densitometry systems are economical in space, conveniently movable (as within a hospital, clinic or physician's office) to a desired temporary location of use, and offer superior safety (owing to low levels of electric current utilization and reduced exposure of personnel to scatter radiation) as well as ease of positioning the x-ray source and detector relative to a patient's extremity for imaging. The various functions and operations of the system are conventionally controlled by buttons or switches on a control panel that is positionally associated with the cart.
X-ray fluoroscopic imaging systems of the type with which the present invention is concerned typically include a processing system, such as a computer, and peripheral devices enclosed within a portable cabinet and a C-arm apparatus that is mounted to the cabinet. The processing system controls the operation of the various components of the imaging system, provides a camera or image processing to transform in real time image data received from an image receptor for display, printing or storage, and communicates with peripheral devices. The computer may also be configured to communicate with a local area network to transfer, for example, image data to locations remote from the sterile environment. An example of a suitable processing system is a personal computer running the Windows 95.RTM., DOS, UNIX, MacOS or other operating systems. Examples of peripheral devices include display monitors, image (or video) printers and image storage devices (or recorders).
The C-arm apparatus includes a C-arm assembly, a support arm assembly and an articulated arm assembly. The C-arm assembly includes a C-arm having a track for guiding rotational movement of the C-arm, an x-ray source assembly including an x-ray source and an x-ray detector assembly including an image receptor and camera. The x-ray source and detector assemblies are located at opposing ends of the C-arm so that the x-ray source and image receptor face each other and x-rays emitted by the x-ray source impinge on the image receptor.
The support arm assembly engages the C-arm track so that the C-arm is movable relative to the support arm, and the articulated arm assembly is provided to facilitate movement of, including change in the angular orientation of, the source and detector assemblies relative to a patient's body portion being imaged. The articulated arm assembly includes at least one movable arm wherein a first end portion of the arm is connected to the support arm assembly and a second end portion of the arm is connected to a mobile base or portable cabinet. Preferably, the first end portion is so connected to the support arm assembly that the support arm assembly can be rotated relative to the movable arm.
During surgical procedures a sterile field is created around a patient to ensure that foreign substances or organisms do not infect the patient. Any instruments or persons within this field have to be sterile or covered by a sterile draping material. The sterile field is generally defined by the American College of Surgeons and published by the Association of Operating Room Nurses (AORN). Generally, the sterile field is defined as the area occupied by the sterile draping material on any operating room table, including the patient table and instrument tables. To permit sterile personnel to position the x-ray fluoroscopic imaging system C-arm assembly in the sterile field a clear surgical drape covers the C-arm assembly.
In the x-ray fluoroscopic imaging system described in U.S. provisional patent application Ser. No. 60/078,491 filed by one of the applicants herein (jointly with other persons) on Mar. 18, 1998, and in U.S. patent application Ser. No. 09/270,373 filed by the same one of the applicants herein (jointly with the same other persons) on Mar. 16, 1999, the entire disclosures of which are both incorporated herein by this reference, to permit surgeons to activate certain functions of the x-ray fluoroscopic imaging system within this sterile field, either the x-ray source assembly or the x-ray detector assembly, which are used within the sterile field, includes a control panel that provides a physician with easy access to predefined imaging control functions associated with the x-ray fluoroscopic imaging system within the sterile field. By locating the control panel on the ends of the C-arm, a surgeon can activate the functions without placing a hand or arm in the path of the x-ray beam. Preferably, the control panel includes an array of membrane switches, wherein each switch in the array is provided to activate a function performed by the x-ray fluoroscopic imaging system. Examples of functions controlled by the control panel switches include: x-ray source activation; image printing; image noise suppression; camera rotation; and x-ray source voltage/current control.
The x-ray fluoroscopic imaging system may also include a foot control panel which is similar to the above-described control panel but permits foot activation of predefined functions of the x-ray fluoroscopic imaging system including but not limited to x-ray activation, image printing and image storing.